Some men never go "bald" but everyone's hair thins out over the years. The
term androgenetic refers to the fact that common balding requires both male hormones (androgens) and a genetic tendency to lose hair. Because there are many genes involved, however, you can't look at your parents and know how much hair you will lose or how fast you will lose it. In particular, the idea that hair loss is passed down from the mother's side of the family is folklore, not fact.

The problem of hair loss has resulted in many other myths and misconceptions. For instance, wearing hats does not "choke off" hair roots and promote baldness. Likewise,
longer hair does not put a strain on roots.

Once you think your hair is thinning, it's worth a check to be sure. Even men
who never lose much hair develop some receding at both temples during
adolescence. Boys' hairlines are straight across; adult men have more of an
M shape.

Many conditioners, shampoos, vitamins, and other products, as well as procedures involving lasers and heat, claim to help hair grow in unspecified ways. These are harmless but useless and not worth the investment. To slow down hair loss, there are just two medically proven options:

Minoxidil (Rogaine): This topical application is
over the counter. No prescription is required. It works best on the crown, less on the frontal region. Available as a 2% solution, minoxidil (available as generic as well) may grow a little hair, but it's better at holding onto what's still there. There are few side effects with Rogaine. The main problem with this treatment is the need to keep applying it twice a day, and most men get tired of it after awhile. This drug also comes in a higher strength, 5%, which may be somewhat more effective. Side effects of minoxidil include occasional irritation as well as unwanted hair growth on the face, especially in the 5% concentration. Internal side effects (headaches, ankle swelling, chest pain) are rare.

Finasteride (Propecia): This is a lower-dose version of a drug that is used to shrink the prostates in middle-aged men. Propecia is taken once a day. Studies show that Propecia slows hair loss effectively and tends to grow more hair as well over time. It's works best for men who still have enough hair to retain. Side effects are uncommon and include decreased libido and difficulties with erection and ejaculation. The rate at which these occur is only slightly higher than the frequency in people not on the drug. They usually disappear when the drug is stopped and may go away even if Propecia is continued. Taking Propecia once a day is easier than applying
Rogaine, though some men prefer not to take a medication long term. There is at present no generic version of Propecia; cost varies depending on the pharmacy, from about $60/month for a
three-month supply and higher.